Chapter Two

Question 1

What does p̂ (p-hat) stand for?

Answer 1

The sample proportion

Question 2

What does p stand for?

Answer 2

The population proportion

Question 3

What is a way to describe two categorical variables in a table?

Answer 3

Two-Way table

Question 4

When is a data set skewed to the right?

Answer 4

When the data is piled up to the left and the tail extends far out the right.

Question 5

When is a data set skewed to the left?

Answer 5

When the data is piled up to the right and the tail extends relatively far out to the left.

Question 6

What is the difference between a symmetric and a bell-shaped distribution?

Answer 6

The bell shaped distribution is both symmetric and bell-shaped, while the symmetric distribution is just symmetric.

Question 7

What does μ (mew) stand for?

Answer 7

The population mean.

Question 8

What does x̄ (x-bar) stand for?

Answer 8

The sample mean.

Question 9

What does n stand for?

Answer 9

The sample size.

Question 10

What does N stand for?

Answer 10

The population size.

Question 11

In a study regarding the catches of all NFL receivers (WR or TE), would n or N be the total number of receivers?

Answer 11

N

Question 12

What does m stand for?

Answer 12

The median.

Question 13

What does resistance mean?

Answer 13

A statistic’s ability to remain unaffected by extreme values.

Question 14

If a graph is skewed to the right, which is larger, the median or the mean?

Answer 14

The mean would be greater.

Question 15

If a graph is skewed to the left, which is larger, the median or the mean?

Answer 15

The median would be greater.

Question 16

What is the symbol for standard deviation of a sample and what does it represent?

Answer 16

s represents the standard deviation (measures how spread out the data are rom the mean.

Question 17

What is the symbol for standard deviation of a sample and what does it represent?

Answer 17

σ represents the standard deviation (measures how spread out the data are rom the mean.

Question 18

What is the formula for the standard deviation of a sample?

Answer 18

S= √ (the sum of (x - x̄) squared / (n - 1)

Question 19

What are the rules for the 95% rule?

Answer 19

95% of the data in a sample from a bell shaped distribution should fall between the values of (x̄ - 2s) and (x̄ + 2s)

Question 20

What is the formula for Z-score?

Answer 20

Z score = (The data value in question - x̄) / s

Question 21

Which should be used as the measure of center for skewed data?

Answer 21

The median.

Question 22

Which should be used as the measure of center for symmetric data?

Answer 22

The mean.

Question 23

What is the formula for the LF and UF?

Answer 23

LF = Q1 - 1.5 (IQR)

UF = Q3 + 1.5 (IQR)

Question 24

Where are the explanatory and response variables located on a scatterplot?

Answer 24

The explanatory on the x - axis
The response on the y - axis

Question 25

What is the symbol r used for?

Answer 25

The sample correlation.

Question 26

What is the symbol ρ (row) used for?

Answer 26

The population correlation.

Question 27

What is the coefficient of determination?

Answer 27

The symbol r squared is the coefficient of determination and it is the percentage of the variation in the y-values that is explained by the linear relationship between x and y.

Question 28

How is sample correlation calculated?

Answer 28

r = (the sum of all (x times y) - (n times x̅ times ȳ)) / ((n -1) times standard deviation of x times standard deviation of y)

Question 29

What is the formula for the residual (error of estimation)?

Answer 29

The actual y value - the y value found using the line of least regression

Question 30

Understand Simpson’s paradox.

Answer 30

See 2.7 notes

Question 31

Understand graphical misrepresentaions.

Answer 31

See 2.7 notes (last page)